No. 5] NEW OR CRITICAL CALCAREOUS ALGÆ. 7 



200— 250 /A in diameter seen from above, and the roof intersscted 

 with a small number of delicate muciferous canals. The concep- 

 tacles at length grow down into the frond in great numbers. I 

 have not seen the sporangia. 



A longitudinal section of a branch shows a rather indistinct 

 stratification, according to a solitar}^ section, the cells 12 — 15 or 

 up to 18 ij. long and 7—9 or up to 11 ij- broad, but on the whole 

 rather varying. 



The species stands very near to L. glaciale, but approaches, 

 on the other hand, certain forms of L. Unger i in habit. 



It has been found at Mororan, Prov. Iburi, on the Pacific 

 coast of Japan, where coald and warm currents mingle. Prof. K. 

 .Mij^abe. No. 7. 



Lithothamnion Dickiei Fosl. mscr. 



Lithothamnion potymorphum Dickie Linn. Soc. Journ. Bot. Vol. X\^ Pag. 452. 

 , imbricatum Dickie, herb. 



In British Museums and Kew Gardens herbarium ar some few 

 mostly fragmentary specimens which partty are named L. imbri- 

 catum partly have been referred b}^ Dickie 1. c. to L. polymorphum. 

 On one of the labels is written: „Lith. imbricatum n. sp. Fronde 

 adnata, super repititim imbricata, lamellis crassis, ramis subhori- 

 zontalibus, compressis, lobatis, apicibus obtusis. Keramidiis minutis, 

 dense aggregatis, hemisphericis. 3—4 inches, much imbricated, 

 lobed and branched. Colour ver}^ pale green". It appears howe- 

 ver, as if Prof. Dickie afterwards has referred the species to L. 

 polymorphum. In Suppl. Alg. Tahiti i) it is mentioned such: „„A 

 calcareous alga in rounded masses forming the bottom in 10 fa- 

 thoms off Great Island (Santa Cruz Major), Zambonga. The dredge 

 came up filled with this masses"". „L. polymorphum''. There- 

 fore, I make free to call this species after Prof. Dickie, who dealt 

 with the algæ from the Challenger expedition. 



1) Dickie, Notes on algæ collncted b}^ H. N. Moseley of H. M. S. ..Challen- 

 ger", chiefly obtained in Torres Straits, Coasts of Japan, and Juan Fernandez. 

 Linn. Soc. Journ. Bot. Vol. XV. Pag. 452 : 8. Algæ eollected on the Reefs 

 of Tahiti. 9. Supplement to preceding collection. 



